Cannabis use in early psychosis is associated with reduced glutamate levels in the prefrontal cortex.

Rationale: Recent studies have shown that cannabis may disrupt glutamate (Glu) signaling depressing Glu tone in frequent users. Current evidence have also consistently reported lower Glu-levels in various brain regions, particularly in the medial prefrontal cortex (mPFC) of chronic schizophrenia patients, while findings in early psychosis (EP) are not conclusive. Since cannabis may alter Glu synaptic plasticity and its use is a known risk factor for psychosis, studies focusing on Glu signaling in EP with or without a concomitant cannabis-usage seem crucial.

White matter microstructure in ultra-high risk and first episode schizophrenia: A prospective study.

There is increasing evidence of white matter (WM) pathology in schizophrenia, but its role at the very early stage of the disorder remains unclear. In an exploration of WM microstructure in ultra-high risk (UHR) subjects and first episode schizophrenia (FES), 34 FES, 27 UHR and 26 healthy control (HC) subjects underwent a magnetic resonance imaging (MRI) tract based spatial statistics (TBSS) investigation. Whole brain fractional anisotropy (FA), mean diffusivity (MD), radial (RD) and axial diffusivity (AD) values were extracted.

Effect of high-potency cannabis on corpus callosum microstructure.

Background: The use of cannabis with higher Δ9-tetrahydrocannabinol content has been associated with greater risk, and earlier onset, of psychosis. However, the effect of cannabis potency on brain morphology has never been explored. Here, we investigated whether cannabis potency and pattern of use are associated with changes in corpus callosum (CC) microstructural organization, in patients with first-episode psychosis (FEP) and individuals without psychosis, cannabis users and non-users.